"The reality is clear. The JCPOA is working – that is a view shared by our European allies, independent experts, and the current U.S. Secretary of Defense," Obama said. "The JCPOA is in America’s interest – it has significantly rolled back Iran’s nuclear program. And the JCPOA is a model for what diplomacy can accomplish – its inspections and verification regime is precisely what the United States should be working to put in place with North Korea."

"I believe that the decision to put the JCPOA at risk without any Iranian violation of the deal is a serious mistake. Without the JCPOA, the United States could eventually be left with a losing choice between a nuclear-armed Iran or another war in the Middle East," the former president said. "In a dangerous world, America must be able to rely in part on strong, principled diplomacy to secure our country. We have been safer in the years since we achieved the JCPOA, thanks in part to the work of our diplomats, many members of Congress, and our allies."

"Iran's hostile actions since its signing have only reaffirmed that it remains dedicated to sowing instability in the region," Ryan said. "The president's announcement today is a strong statement that we can and must do better."

"The President's decision to follow his misguided and uninformed campaign promise to destroy the successful Joint Comprehensive Plan of Action endangers global security and defies comprehension," Pelosi said. "Our allies will hold up their end of the agreement, but our government will lose its international credibility and the power of our voice at the table."

Rep. Adam Schiff says the United States' withdrawal will "undermine our national security."

On the other hand, former Gov. and TBN host Mike Huckabee says the "Iran deal is deader than Osama bin Laden."

Sen. Orrin Hatch says he applauds the President's announcement because he believes the deal is "deeply problematic."

Sen. Bill Nelson says that while he agrees that "more pressure" should be on Iran to "stop them from developing their ICBM missiles," he disagrees with pulling out of the deal.

"We need to put more pressure on Iran with additional economic sanctions to stop them from developing their ICBM missiles, but pulling out of this deal now is a tragic mistake," Nelson said. "It will divide us from our European allies and it will allow Iran to build a nuclear bomb within a year instead of preventing it for at least seven to 12 years."

Sen. John Barrasso believes "strategic patience with Iran has failed." The senator continued in a tweet saying, "Iran has continued to terrorize & threaten its neighbors."

Rep. Marsha Blackburn says "Iran is a terrorist state whose desire to destroy Israel and undermine the security of the U.S. is well known." The representative from Tennessee applauded President Trump in a video posted on her Twitter page.

Rep. Elizabeth Warren says President Trump's decision to withdraw undermines the "landmark agreement to prevent Iran from obtaining a nuclear weapon." Warren also believes this deal will empower "Iranian hardliners and doesn't make use safer."

Sen. Thom Tillis says Trump's decision "provides a new opportunity for America to alleviate the concerns of our allies in the Middle East by ending the experiment of appeasement and holding Iran accountable for its belligerence."

"The President is also reimposing sanctions, which were effective in weakening the Iranian regime and bringing them to the negotiating table in the first place. The Iranian regime’s threat to peace and stability is real: we cannot repeat the mistakes and miscalculations of the past," Tillis said.

“President Trump has been consistent and clear that this Administration is resolved to addressing the totality of Iran’s destabilizing activities. We will continue to work with our allies to build an agreement that is truly in the best interest of our long-term national security," Treasury Department secretary Steve Mnuchin said in a statement. "The United States will cut off the IRGC’s access to capital to fund Iranian malign activity, including its status as the world’s largest state sponsor of terror, its use of ballistic missiles against our allies, its support for the brutal Assad regime in Syria, its human rights violations against its own people, and its abuses of the international financial system.”

Republican Chair of House Armed Services Subcommittee on Tactical Air and Land Forces Mike Turner says the deal is a "deeply flawed agreement" but also believes "without proof that Iran is in violation of the agreement, it is a mistake to fully withdraw from this deal."

Saudi Arabia's ambassador to the United States, Khalid bin Salman, says his country fully supports President Trump's plan because they "had reservations with regards to sunset clauses, ballistic missiles program, and Iran’s support for terrorism in the region."

Utah Republican candidate for Senate Mitt Romney says "nothing short of a permanent elimination of Iran's nuclear weapon program is acceptable." Romney also says "its effectiveness will depend in large measure on the cooperative action of our allies and the impact of new sanctions."

Sen. Chuck Grassley says the nuclear deal negotiated by the Obama administration "was an example of leading from behind on foreign policy."

"When negotiations began, the United States was in a position of strength because sanctions were hurting Iran. But President Obama, in his desire to get a deal, weakened America’s position by agreeing to one-sided concessions in return for worthless commitments from a deceitful and repressive regime," Grassley said. "We now know Iran was driving full speed ahead in developing nuclear weapons. By pulling the U.S. out of this badly negotiated deal, President Trump is putting America back in a position of strength and showing the kind of global leadership the country needs as it approaches challenges, not only from Iran, but also from nations like North Korea, Russia and China.”

"The agreement, negotiated by then-President Obama, lacks basic oversight and enforcement, and allows a dishonest Iran to continue its destabilizing activity and potentially restart its nuclear weapons program at the sunset of the JCPOA. Iran continues to pose a serious threat, not only on the global stage as they are allowed to advance their unfettered ballistic missile capacities, but also in the Middle East," Ernst said. "We know that Iran continues to support and finance terrorist organization proxies that destabilize the region, endangering American servicemembers and our partners. I am encouraged by the President’s decision to withdraw from the JCPOA today, and have full confidence that the President and Secretary Pompeo will work with Congress to develop a comprehensive strategy that permanently addresses the threat that a nuclear-capable Iran poses to U.S. and international security.”

Former Mexican president Vicente Fox believes "President Trump made the U.S. democracy look like a toy he can play with. There's no one to stop or prevent his rants, he says one thing now and shortly, he changes his mind causing uncertainty in the world."

"It's a shame how the U.S. has lost its place in the world," Fox said.

Sen. Mark Warner, who serves on the intel committee, says "withdrawing from the Iran deal makes the United States, and the world, less secure."

Former secretary of state John Kerry, who helped negotiate this deal, says "today's announcement weakens our security, breaks America's word, isolates us from our European allies, puts Israel at greater risk, empowers Iran's hardliners, and reduces our global leverage to address Tehran's misbehavior, while damaging the ability of future Administrations to make international agreements."